Saddle building is an ancient art. The typical saddle is built up on a shaped saddle tree, on to which are mounted various layers of leather (or leather substitute), and padding, some of these elements being partly decorative as well as functional, and the whole assembly is attached to a saddle skirt. Depending upon the particular style and materials of construction, such a saddle may weigh between twenty-five and fifty pounds and involve considerable amounts of hand labor in its construction. The latter circumstance makes the typical saddle an expensive item, while the former makes it difficult for slightly-built persons, such as abolescents, to handle, as well as increasing the load on the saddled animal.